Winter melt conditions of the inland ice cap on King George Island, Antarctic Peninsula

Erdkunde ◽  
2015 ◽  
Vol 69 (4) ◽  
pp. 341-363 ◽  
Author(s):  
Ulrike Falk ◽  
Hernán Sala
Keyword(s):  
Antarctic Peninsula ◽  
King George Island ◽  
Ice Cap ◽  
Inland Ice

The geology of King George Island, South Shetland Islands: uniting local geological maps and stratigraphical columns

2021 ◽  
Author(s):  
Bastian Lopez ◽  
Joaquin Bastias ◽  
Daniela Matus ◽  
Ricardo Jaña ◽  
Marcelo Leppe
Keyword(s):  
Antarctic Peninsula ◽  
South Shetland Islands ◽  
King George Island ◽  
The South ◽  
Moby Dick ◽  
Shetland Islands ◽  
Ice Cap ◽  
The North ◽  
South Shetlands ◽  
Geological Map

<p>King George Island is the largest one of the South Shetland Islands group distributed parallel to and separated by the Bransfield Strait of the northern tip of Antarctic Peninsula. The archipelago of the South Shetlands is mainly composed of the products of the active margin developed as a result of the subduction of the Phoenix Plate beneath the continental crust of the Antarctic Peninsula (e.g. Barker, 1982; Bastias et al., 2019). The lithologies are largely dominated by Mesozoic and Cenozoic sedimentary and volcanic successions that are cut by a few hypabyssal plutons. While some authors have suggested a southwest to northeast trend along the archipelago from older to younger magmatic activity (e.g. Haase et al., 2012), others have indicated that some of the magmatic events may have been recorded along the entire archipelago (e.g. Valanginian arc rocks; Bastias et al., 2019). Regardless, King George Island hosts an exceptional stratigraphical record of the Cenozoic period. Moreover, this island is mostly covered by an ice cap at the present day, which is commonly terminated with ice cliffs around much of the island. The southern edge of the island host Mesozoic and Paleogene successions, these rocks are dominated by volcanic and volcaniclastic units. The rocks in King George Island are generally young to the east and to the north ends. Cape Melville, the southeast extreme of the island, hosts the youngest sedimentary rocks known on the island: the Moby Dick Group (Birkenmajer, 1985).</p><p>While several authors have presented local studies in the King George Island over the last three decades, an integrated assessment of the outcropping units in the entire island remains unexplored. A new geological map for King George Island will allow to update the current understanding of the stratigraphy of the South Shetland Islands, which will help to support not only the geological studies but also those focused on the environmental and paleontological record.</p><p>Barker, 1982. Journal of the Geological Society 19, 787-801. (DOI: 10.1144/gsjgs.139.6.0787)</p><p>Bastias et al. (2019). International Geology Review 62 (11), 1467-1484. (DOI: 10.1080/00206814.2019.1655669)</p><p>Birkenmajer (1985). Bulletin Polish Academic Earth Sciences 33:15-23.</p><p>Haase et al. (2012). Contributions to Mineralogy and Petrology 163, 1103-1119. (DOI: 10.1007/s00410-012-0719-7).</p>

scholarly journals Site information and initial results from deep ice drilling on Law Dome, Antarctica

1997 ◽  
Vol 43 (143) ◽  
pp. 3-10 ◽  
Author(s):  
V.I. Morgan ◽  
C.W. Wookey ◽  
J. Li ◽  
T.D. van Ommen ◽  
W. Skinner ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Sheet ◽  
High Accumulation ◽  
Ice Flow ◽  
Ice Cap ◽  
Basal Ice ◽  
Inland Ice ◽  
The Last Glacial Maximum ◽  
Initial Results ◽  
The Last Glacial

AbstractThe aim of deep ice drilling on Law Dome, Antarctica, has been to exploit the special characteristics of Law Dome summit, i.e. low temperature and high accumulation near an ice divide, to obtain a high-resolution ice core for climatic/environmental studies of the Holocene and the Last Glacial Maximum (LGM). Drilling was completed in February 1993, when basal ice containing small fragments of rock was reached at a depth of 1196 m. Accurate ice dating, obtained by counting annual layers revealed by fine-detail δ18О, peroxide and electrical-conductivity measurements, is continuous down to 399 m, corresponding to a date of AD 1304. Sulphate concentration measurements, made around depths where conductivity tracing indicates volcanic fallout, allow confirmation of the dating (for Agung in 1963 and Tambora in 1815) or estimates of the eruption date from the ice dating (for the Kuwae, Vanuatu, eruption ~1457). The lower part of the core is dated by extrapolating the layer-counting using a simple model of the ice flow. At the LGM, ice-fabric measurements show a large decrease (250 to 14 mm2) in crystal size and a narrow maximum in c-axis vertically. The main zone of strong single-pole fabrics however, is located higher up in a broad zone around 900 m. Oxygen-isotope (δ18O) measurements show Holocene ice down to 1113 m, the LGM at 1133 m and warm (δ18O) about the same as Holocene) ice near the base of the ice sheet. The LGM/Holocene δ18O shift of 7.0‰, only ~1‰ larger than for Vostok, indicates that Law Dome remained an independent ice cap and was not overridden by the inland ice sheet in the Glacial.

Phytoplankton in the embayments of King George Island (Antarctic Peninsula): a review with emphasis on diatoms

Polar Record ◽  
2018 ◽  
Vol 54 (2) ◽  
pp. 158-175 ◽  
Author(s):  
Priscila Kienteca Lange ◽  
Ryszard Ligowski ◽  
Denise Rivera Tenenbaum
Keyword(s):  
Antarctic Peninsula ◽  
Early Summer ◽  
Western Antarctic Peninsula ◽  
King George Island ◽  
Accurate Identification ◽  
Phytoplankton Assemblages ◽  
Marine Food Web ◽  
Planktonic Diatoms ◽  
Local Material ◽  
Marine Food

ABSTRACTConsidering that phytoplankton assemblages are good bioindicators of environmental conditions, the sensitivity of the Western Antarctic Peninsula (WAP) to climate change, and the importance of some areas of its islands as Antarctic Specially Managed Areas, this work assembles published datasets on phytoplankton biodiversity and ecology in confined coastal areas (embayments) of King George Island, WAP. Over 33 years (1980–2013), 415 species from 122 genera have been identified to species level, being mostly diatoms (371 species), with 10 new species described with local material (6 diatoms, 4 cyanobacteria). The importance of diatoms was indicated by the frequent occurrence of Corethron pennatum, Pseudogomphonema kamtshaticum, and abundant benthic genera in the plankton (e.g. Navicula, Cocconeis). The increased contribution of dinoflagellates after 2010 suggests marked changes in the water column. Early-summer blooms differ between the bays' eastern and western shores, with terrestrial melting and wind-driven upwelling inducing the dominance of benthic species at eastern shores, whereas planktonic diatoms (Thalassiosira, Pseudo-nizschia, and Chaetoceros) are most abundant along western shores and central areas. The importance of an accurate identification of organisms that are becoming key ecological components of the region is discussed, as recent changes in the microflora may affect the entire marine food web.

scholarly journals Mesospheric front observations by the OH airglow imager carried out at Ferraz Station on King George Island, Antarctic Peninsula, in 2011

2018 ◽  
Vol 36 (1) ◽  
pp. 253-264 ◽  
Author(s):  
Gabriel Augusto Giongo ◽  
José Valentin Bageston ◽  
Paulo Prado Batista ◽  
Cristiano Max Wrasse ◽  
Gabriela Dornelles Bittencourt ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Near Infrared ◽  
Middle Atmosphere ◽  
Convective Cloud ◽  
Atmospheric Composition ◽  
Secondary Wave ◽  
King George Island ◽  
Composition And Structure ◽  
Waves And Tides ◽  
Energy And Momentum

Abstract. The main goals of this work are to characterize and investigate the potential wave sources of four mesospheric fronts identified in the hydroxyl near-infrared (OH-NIR) airglow images, obtained with an all-sky airglow imager installed at Comandante Ferraz Antarctic Station (EACF, as per its Portuguese acronym) located on King George Island in the Antarctic Peninsula. We identified and analyzed four mesospheric fronts in 2011 over King George Island. In addition, we investigate the atmospheric background environment between 80 and 100 km altitude and discuss the ducts and propagation conditions for these waves. For that, we used wind data obtained from a meteor radar operated at EACF and temperature data obtained from the TIMED/SABER satellite. The vertical wavenumber squared, m2, was calculated for each of the four waves. Even though no clearly defined duct (indicated by positive values of m2 sandwiched between layers above and below with m2  < 0) was found in any of the events, favorable propagation conditions for horizontal propagation of the fronts were found in three cases. In the fourth case, the wave front did not find any duct support and it appeared to dissipate near the zenith, transferring energy and momentum to the medium and, consequently, accelerating the wind in the wave propagation direction (near to south) above the OH peak (88–92 km). The likely wave sources for these four cases were investigated by using meteorological satellite images and in two cases we could find that strong instabilities were potential sources, i.e., a cyclonic activity and a large convective cloud cell. In the other two cases it was not possible to associate troposphere sources as potential candidates for the generation of such wave fronts observed in the mesosphere and secondary wave sources were attributed to these cases. Keywords. Atmospheric composition and structure (airglow and aurora) – meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides)

Influence of Climate Variability in King George Island Glacier Retreat – Antarctic Peninsula

2021 ◽  
Author(s):  
Ibeth Celia Rojas Macedo ◽  
Wilson Alfredo Suarez Alayza ◽  
Edwin Anibal Loarte Cadenas ◽  
Katy Damacia Medina Marcos
Keyword(s):  
Climate Variability ◽  
Antarctic Peninsula ◽  
Enso Event ◽  
Glacier Retreat ◽  
Glacier Mass Balance ◽  
Climatic Data ◽  
King George Island ◽  
Cooling Period ◽  
Glacier Shrinkage ◽  
Landsat Satellite

&lt;p&gt;This research aims to explain the influence of climatic variables (temperature and precipitation) in King George Island (KGI) glacier shrinkage on the Antarctic Peninsula. It employed Landsat satellite images from 1989 to 2020, climatic data and ONI index from 1980 to 2019.&lt;/p&gt;&lt;p&gt;King George Island glaciers have lost 10% of their coverage in the last 31 years. Greater glacier shrinkage was shown until the first mid-period assessed, while the retreat rate slowed down for the second half of the studied period. Furthermore, of 73 KGI glaciers, 37% were marine- and land-terminating, 42% were land-terminating and 21% were sea-terminating. Nonetheless, the decreases in the ice-coverage of marine-contact glaciers (35% of glacier coverage reduced) were higher than land-terminating glaciers (17% of glacier coverage reduced).&lt;/p&gt;&lt;p&gt;There was a perceivable fluctuation in annual average air temperature for the 1980-2006 period. Nevertheless, from around 2007 to 2015/2016 there was a slight continuous cooling period and precipitation was somewhat above the average. Therefore, these patterns could explain the recent KGI glacier-retreat deceleration.&lt;/p&gt;&lt;p&gt;Unlike the 1982/1983 and 1997/1998 El Ni&amp;#241;o events, the 2015/2016 El Ni&amp;#241;o was colder with precipitation reduction from the sustained annual amount (since roughly 2007 to 2015/2016) to values below the average. Moreover, during the 2015/2016 El Ni&amp;#241;o, KGI glacier coverage reduction was the lowest for the 31 year-long evaluated. However, it was revealed that the glacier's height could increase by accumulation in El Ni&amp;#241;o years, but glacier mass balance could be more negative due to basal melting. Additionally, land-terminating glaciers have lost more glacier coverage than sea-terminating glaciers throughout this ENSO event.&lt;/p&gt;&lt;p&gt;Hence, climate variability might play a significant role in KGI glacier shrinkage, but calving process, glacier features and so on, further a combination of them should be assessed to reach a better understanding of KGI glacier retreat.&lt;/p&gt;

Debris recorded in ice free areas of an Antarctic Specially Managed Area (ASMA): Admiralty Bay, King George Island, Antarctic Peninsula

2009 ◽  
Vol 4 (1) ◽  
pp. 36-39 ◽  
Author(s):  
Martin Sander ◽  
Erli Costa ◽  
Tatiana Balbão ◽  
Ana Paula Carneiro ◽  
César Santos
Keyword(s):  
Antarctic Peninsula ◽  
King George Island ◽  
Admiralty Bay

scholarly journals Kelp gulls, Larus dominicanus (Aves: Laridae), breeding in Keller Peninsula, King George Island, Antarctic Peninsula

2009 ◽  
Vol 26 (3) ◽  
pp. 562-566 ◽  
Author(s):  
Joaquim O. Branco ◽  
Erli S. Costa ◽  
Jansen de Araujo ◽  
Edison Durigon ◽  
Maria Alice S. Alves
Keyword(s):  
Antarctic Peninsula ◽  
King George Island ◽  
Larus Dominicanus

scholarly journals Development of radar glacier zones on the King George Island ice cap, Antarctica, during austral summer 1996/97 as observed in ERS-2 SAR data

2000 ◽  
Vol 31 ◽  
pp. 357-363 ◽  
Author(s):  
Matthias Braun ◽  
Frank Rau ◽  
Helmut Saurer ◽  
Hermann Gobmann
Keyword(s):  
Meteorological Data ◽  
Austral Summer ◽  
Late Summer ◽  
Ground Truth ◽  
King George Island ◽  
Equilibrium Line Altitude ◽  
Sar Images ◽  
Ice Cap ◽  
Wet Snow ◽  
Frozen Percolation

AbstractBased on a time series of European remote-sensing satellite (ERS-2) synthetic-aperture radar (SAR) images from 1996/97, ablation on the King George Island (Antarctica) ice cap is documented. Snowmelt patterns were monitored by mapping the dynamic evolution of radar glacier zones and their boundaries. On the ice cap, all major radar glacier zones except the dry-snow radar zone were identified during the observed period While winter was characterized by a frozen-percolation radar zone, the ablation season was characterized by wet-snow and bare-ice radar zones. A striking bright backscatter signature indicated the presence of a highly reflective zone in the lower parts of the wet-snow zone. It was attributed to a phase 2 melt (P2) radar zone, which is characterized by a metamorphosed and roughened surface of a melting snow cover. Due to the absence of simultaneously acquired ground-truth information, concurrent meteorological data proved to be essential for interpreting the SAR images. Although the maximum elevation of the ice cap does not exceed 680 ma.s.L, ablation patterns obviously reflect altitudinal control. Melt onset up to 530 m a.s.l. was initiated by an advection event at the end of October 1996. A wet snowpack on the entire ice cap corresponds with a prolonged period of high temperatures in January 1997. However, the highest parts of the ice cap were affected by occasional melt-freeze cycles. The transient snowline at the end of February was determined as being at 250 m a i l. This late-summer snowline was regarded as an approximation of the equilibrium-line altitude for the 1996/97 ablation season.

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